Seat cushion

ABSTRACT

The seat cushion comprises a central slab of cellular material having marginal zones, and two side members of cellular material each having a projecting edge portion with a free extremity, the projecting edge portion of each said side member covering a respective marginal zone of said central slab and said cellular material of said central slab being of greater resiliency than said cellular material of said side members.

United States Patent Georges Chrktin Marnes-La-Coquette, France 802,601

Feb. 26, 1969 Oct. 19, 1971 Etablissments Bertrand Faure Puteaux, FranceFeb. 27, 1968 France Inventor App]. No. Filed Patented Assignee PrioritySEAT CUSHION 7 Claims, 7 Drawing Figs.

U.S. I 297/452, 297/459 Int. Cl A47c 3/00, A47c 7/ 14, B60n 1/06 Fieldof Search 297/418,

[56] References Cited UNITED STATES PATENTS 3,111,345 11/1963 Peras297/455 3,175,863 3/1965 Hood 297/455 3,208,085 9/1965 Grimshaw 297/452X 3,257,149 6/ 1966 Fruchte et al.. 297/452 3,487,134 12/1969 Burr264/45 Primary Examiner-Casmir A. Nunberg Attorneys-Waters, Roditi,Schwartz and Nissen ABSTRACT: The seat cushion comprises a central slabof cellular material having marginal zones, and two side members ofcellular material each having a projecting edge portion with a freeextremity, the projecting edge portion of each said side member coveringa respective marginal zone of said central slab and said cellularmaterial of said central slab being of greater resiliency than saidcellular material of said side members.

PATENTEDBCI 19 new v 3.614.159

I sum 3 0F 3 tomobile vehicles, each of the two parts of the seat (seatportion and back portion) is constituted by a rigid frame carrying aresilient structure of metallic springs itself covered by a foamcushion. In the most frequent case this foam cushion is formed in asingle block, which excludes the possibility of varying locally theresilience of the supporting surface of the cushion in accordance withthe respective roles played at the various parts of the surface.

In an advantageous modification it has been proposed to form the saidcushion with the aid of separate blocks of foam of different resilience,the blocks comprising a central slab which is relatively resilient andtwo finner side members. But in this modification the said blocks werejuxtaposed along vertical planes, which presented in particular twodisadvantages both of which are due to the differences between thedefonnabilities of the juxtaposed blocks on one side and the other ofthese planes. On the one hand the part of the supporting surfacedisposed perpendicularly to each plane of juxtaposition constitutes arelatively hard line felt to be disagreeable by the seated person and onthe other hand, when the cushion is loaded merely by supporting a seatedperson, the juxtaposed blocks tend to separate from one another bycleavage, causing the appearance between them of gaps the width of whichincrease with time.

According to the invention there is provided a seat cushion composed ofseparate blocks made from cellular materials of different resiliences,the blocks comprising a relatively resilient central slab and two firmerside members with each side member including a projecting edge coveringa marginal zone of the central slab. The projecting edge of each sidemember preferably decreases progressively in thickness towards its freeextremity and the said marginal zones of the central slab are preferablyset back in the central slab.

The cushion preferably also includes an end pad (front pad if it is fora seat portion, upper pad if it is for a back portion) made from acellular material more resilient than the central slab, this padincluding a projecting edge of the type defined above for the sidemembers.

It is further preferred that each of the different blocks constitutingthe cushion should be formed by moulding with a finishing skin extendingover at least all that part of its external surface exposed at theexterior of the completed cushion. The adjacent and juxtaposable facesof the various blocks preferably have complementary shapes receivableone within the other, and, in seats or seat portions comprising a rigidsupporting frame and a cushion such as defined above, the framepreferably directly supports the periphery of the central slab of thecushion.

The projecting edges provided on the side members of the seat inaccordance with the invention remedy the various drawbacks of theabove-mentioned prior constructions; the resilience of the supportingsurface, being the resultant of the FIGS. 2, 3, 4 and 5 show in moredetail such a seat in accordance with the invention, being respectivelya perspective view with parts removed, vertical sections on the linesill-ll! and lV-lV of FIG. 2 and a horizontal section on the line V V ofFIG. 2.

FIG. 6 shows an element of this and FIG. 7 shows in perspective view abench seat for two places made in accordance with the invention. In thepractical form of the seat cushion illustrated in the drawings, theindependent seat in perspective view,

blocks of foam comprise:

resiliences of the superposed blocks parts of blocks) that it covers,varies progressively along this surface from the relatively firm-sidesto the relatively resilient center of the cushion, especially if thethickness of the projecting edges varies progressively. Further, thelateral coverage effected by each edge practically excludes the risk ofseparation by cleavage.

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1 shows diagrammatically, in vertical cross section, a seat portionof a seat for one place made in accordance with the invention.

a central slab (la or lb, the index a being used for the elementsconstituting the seat portion and the index b for the elementsconstituting the back portion) formed from a relatively resilient foamand intended to support the greater part of the weight of the seatedperson P,

two firmer sides (2aor 2b) adjoining this slab laterally and having themain object of keeping the seated person in place and preventing swayingmovements when the vehicle turns,

and preferably also a pad (3aor 3b) more resilient than the central slaband constituting the free end of the cushion (front end for the seatportion, upper end for the back portion), the function of this pad beingto support resiliently either the thighs or the nape of the neck of theseated person, the upper pad 3balso constituting a safety padding forthe rear passengers when it equips a back portion of a front seat of thevehicle.

The blocks are covered, finishing skin 4.

The said skin is advantageously made by moulding with the correspondingblocks in a manner known in itself. For this purpose it is sufficient inaccordance with the technique known as integral foam, to inject coldinto a shaped mould (advantageously pitted with the negative impressionof the outer surfaces of an actual skin and its seams) a polyol and anisocyanate in such manner as to form a polyurethane foam by the reactionbetween these two-substances.

However, this skin 4 mayalso be applied to the working face of each foamblock by any suitable process alter the moulding of this block, which isrelatively easy since the said face does not in general have anyreentrant zone.

As can be seen from the Figures, it is preferred that the juxtaposedfaces of the various blocks should have complementary profiles such thatthey may fit exactly one into the other.

An advantageous profile is that described by a straight line movingparallel to itself alonga zigzag line with rounded angles including atleast one Z.

A projecting edge 5 is included in each of the peripheral blocks, whichedge in its final position covers a marginal zone 6, preferably slightlyset back, of the central slab.

The thickness of this edge preferably decreases up to its free extremityand its width is preferably greater than 5 cm, that is to say at leastequal to half the total width of the block of which it forms a part.

The assembly of the blocks against one another is eflected in anydesired manner, in particular by sticking, or with the aid of springclips 7 fixed in one of the blocks and cooperating with rigid seatings 8fixed in the adjacent block.

The assembly of the two lateral blocks (2a or Zbof a cushion could beconstituted by a single block of U-shaped or be in the fonn of a framesurrounding the central slab and furnished in preferably individually,with a dividually with its finishing skin.

The assembly of blocks forming each cushion is mounted in any desiredmanner on a rigid frame 9 and its resilient structure comprising springs10, for example with the aid of other clips 1] fixed in some of the saidblocks.

Each of the cushions thus obtained by juxtaposition of the cushion maybe located naturally at the junction zones between the various adjacentblocks; one can therefore avoid emphasizing these lines by piping, as isoften necessary in conventional cushions.

The supporting frame 9 preferably has external dimensions in particulara width-appreciably smaller than the corresponding dimensions of thesaid cushion.

Such an arrangement is made possible by the choice, explained above, ofa relatively firm foam for making the sides of the cushion that projectover the said frame, such that these sides are not liable to give wayalthough arranged so as to overhang slightly.

It has the considerable advantage that one is able to use one and thesame standard frame for making a large number of cushions of differentappearance and/or dimensions by simple modification of the shapes anddimensions of at least some of the peripheral foam blocks forming thecushion supported by this frame; in particular there may be used twoabsolutely identical frames for making the seat portions (or the backportions) of the two left and right front seats of an automobilevehicle, having for example symmetrical shapes relative to the verticallongitudinal medial frame of the vehicle.

It is such an arrangement that has been illustrated in the drawings.

The frame 9 substantially matches the periphery of the central slab Inor lb, the said periphery resting directly on this frame. The remainderof'the slab is supported by the structure having springs 10. As regardsthe sides (2a, or 2b) and the pads (3a, 3b), they project at leastpartly over the exterior of the frame, for a distance d between 3 and 5cm. In this case, if we consider the cross section of a side or pad, thepoint of the said side disposed highest and most externally of thecushion is advantageously spaced by more than cm. from the frame, whichleaves a good thickness of foam between the rigid frame and thesupporting surface.

The frame itself is advantageously in the form of a rectangular framemade with the aid of rigid angle members 13 (FIGS. 2 to 6) the profileof which is in the shape of a Z drawn out like a step. This frame isreinforced at its four corners by brackets 14.

Further, the two frames corresponding respectively to the seat portionand the back portion of a seat carry small plates (l5, l6) suitable forsupporting a system for the articulation of the back portion to the seatportion, the system being adjustable, for example by rotation of anexternal knob 18 easily accessible by the seated person.

Each frame may further comprise suitable anchorage points for otherelements, such as a rest or rails adapted for sliding in guides in theflooring of the vehicle.

Of course, the principles explained above are applicable perfectly wellto bench seats for several places.

It is in this way that the rear bench seat 7 of the vehicle, shown inFIG. 7, has been made, in which seat there are foam blocks individuallycovered as has been explained above, viz. resilient slabs la, lb, firmersides 2a, 2b (which are here three in number, one of the three sidesextending to the center of the bench seat) and front and upper pads 3aand 3b.

As is evident, and as also emerges from the foregoing, the invention isin no way limited to those applications or practical fonns of itsvarious parts that have been particularly illustrated; on the contrary,it includes all modifications, in particular those in which the cellularmaterial is constituted by a resilient substance other than a foam (ofpolyurethane or other substance), for example a resilient fibrousstructure whether or not impregnated with foam, and those in which theseats are intended for purposes other than for equipping a vehicle, forexample for home furnishing.

lclaim:

l. A seat cushion comprising a central slab of cellular material havinga person-supporting external surface bonded by marginal zones, and twoside members of cellular material each having a projecting edge portionwith a free extremity,

the projecting edge portion of each said side members covermg arespective said marginal zone of said external surface of said centralslab, the juxtaposed faces of said marginal zone and said edge portionhaving complementary zigzag profiles in a plane perpendicular to saidfaces and said cellular material of said central slab being of greaterresiliency than said cellular material of said side members. a 1

2. A seat cushion comprising a central slab of cellular material havinga person-supporting external surface bounded by marginal zones set backtherein, and two side members of cellular material each having aprojecting edge portion with a free extremity, the projecting edgeportion of each said side member covering a respective said marginalzone of said 'external surface of said central slab, the juxtaposedfaces of said marginal zone and said edge portion having complementaryzigzag profiles in a plane perpendicular to said faces and said cellularmaterial of said central slab being of greater resiliency than saidcellular material of said side members.

3. A seat cushion as defined in claim 2 wherein said projecting edgeportion of each said side member decreases in thickness towards its freeextremity.

4. A seat cushion comprising a central slab of cellular material havingmarginal zones, and two side members of cellular material each having aprojecting edge portion with a free extremity, the projecting edgeportion of each said side member covering a respective marginal zone ofsaid central slab and said cellular material of said central slab beingof greater resiliency than said cellular material of said side membersand including a terminal pad of cellular material having a projectingedge portion with a free extremity, said projecting edge portion of saidterminal pad covering a marginal zone of said central slab adjacent saidmarginal portions of said central slab covered by said projecting edgeportions of said side members and said cellular material of saidterminal pad being of greater resiliency than said cellular material ofsaid central slab.

5. A seat cushion as defined in claim 4 wherein each of said projectingedge portions decreasing in thickness towards its free extremity.

6. A seat cushion comprising a central slab of cellular material havingmarginal zones, and two side members of cellular material each having aprojecting edge portion with a free extremity, the projecting edgeportion of each said side member covering a respective marginal zone ofsaid central slab, and said cellular material of said central slab beingof greater resiliency than said cellular material of said side memberswherein said central slab and each said side member abut at aninterface, said interface defining in section perpendicular thereto azigzag line with rounded edges including at least one Z.

7. A seat having a seat portion and a back portion at least one of whichportions comprises a frame and a seat cushion supported on said frame,said seat cushion comprising a central slab of cellular material havinga person-supporting external surface bounded by marginal zones, and twoside members of cellular material each having a projecting edge portionwith a free extremity, the projecting edge portion of each said sidemember covering a respective marginal zone of said external surface ofsaid central slab, the juxtaposed faces of said marginal zone and saidedge portion having complementary zigzag profiles in a planeperpendicular to said faces and said cellular material of said centralslab being of greater resiliency than said cellular material of saidside members and said frame directly supporting the periphery of saidcentral slab.

1. A seat cushion comprising a central slab of cellular material havinga person-supporting external surface bonded by marginal zones, and twoside members of cellular material each having a projecting edge portionwith a free extremity, the projecting edge portion of each said sidemembers covering a respective said marginal zone of said externalsurface of said central slab, the juxtaposed faces of said marginal zoneand said edge portion having complementary zigzag profiles in a planeperpendicular to said faces and said cellular material of said centralslab being of greater resiliency than said cellular material of saidside members.
 2. A seat cushion comprising a central slab of cellularmaterial having a person-supporting external surface bounded by marginalzones set back therein, and two side members of cellular material eachhaving a projecting edge portion with a free extremity, the projectingedge portion of each said side member covering a respective saidmarginal zone of said external surface of said central slab, thejuxtaposed faces of said marginal zone and said edge portion havingcomplementary zigzag profiles in a plane perpendicular to said faces andsaid cellular material of said central slab being of greater resiliencythan said cellular material of said side members.
 3. A seat cushion asdefined in claim 2 wherein said projecting edge portion of each saidside member decreases in thickness towards its free extremity.
 4. A seatcushion comprising a central slab of cellular material having marginalzones, and two side members of cellular material each having aprojecting edge portion with a free extremity, the projecting edgeportion of each said side member covering a respective marginal zone ofsaid central slab and said cellular material of said central slab beingof greater resiliency than said cellular material of said side membersand including a terminal pad of cellular material having a projectingedge portion with a free extremity, said projecting edge portion of saidterminal pad covering a marginal zone of said central slab adjacent saidmarginal portions of said central slab covered by said projecting edgeportions of said side members and said cellular material of saidterminal pad being of greater resiliency than said cellular material ofsaid central slab.
 5. A seat cushion as defined in claim 4 wherein eachof said projecting edge portions decreasing in thickness towards itsfree extremity.
 6. A seat cushion comprising a central slab of cellularmaterial having marginal zones, and two side members of cellularmaterial each having a projecting edge portion with a free extremity,the projecting edge portion of each said side member covering arespective marginal zone of said central slab, and said cellularmaterial of said central slab being of greater resilIency than saidcellular material of said side members wherein said central slab andeach said side member abut at an interface, said interface defining insection perpendicular thereto a zigzag line with rounded edges includingat least one Z.
 7. A seat having a seat portion and a back portion atleast one of which portions comprises a frame and a seat cushionsupported on said frame, said seat cushion comprising a central slab ofcellular material having a person-supporting external surface bounded bymarginal zones, and two side members of cellular material each having aprojecting edge portion with a free extremity, the projecting edgeportion of each said side member covering a respective marginal zone ofsaid external surface of said central slab, the juxtaposed faces of saidmarginal zone and said edge portion having complementary zigzag profilesin a plane perpendicular to said faces and said cellular material ofsaid central slab being of greater resiliency than said cellularmaterial of said side members and said frame directly supporting theperiphery of said central slab.